There are some kinds of different fluids in our known world. I will try to categorize them in respect to their color.
To begin with, there are green fluids. I did not find many different kinds of green fluids.
In fact, I just found one. It's a mysterious thing, known as "slime" to the ordinary population. This "slime" has strange properties. On the one hand, it is nice to look at, on the other hand, it is poisonous, it doesn't smell nor taste well and it is sticky.
The second kind of fluids are brown. There are several types of brown fluids.
The first one is called "beer". It is, to say, one of the real bad substances in our known world: It is tasty, it smells well and everyone likes it. But beware! It makes addicted! Once you drank a potion of it you won't be able to control your senses anymore! You won't even be able to walk on a line! So, if possible, avoid this fluid. Just imagine you were hunting and your life depends on your reaction, on your movement, and on your visual impressions!
I am not quite sure, but I suppose, this "beer" does not have human root. No one is able to produce it. Nevertheless, there are hundreds, thousands of potions arround this world? Where do they come from? Who is interested in drunken hunters? The answer is quite obvious: The demon! Beer is an invention of the demon!
There is another very mysterious fluid here in Tibia. People tend to call it "oil". I really don't know what to do with it. It smells strange; if you know how to put it on fire, it burns quite fine (it's not easy, but once it burns it is very hot!).
Avoid steping on a pool of oil - it's very slippery. That leads me to an idea: My watch doesn't work anymore since yesterday - maybe I should try to throw it in a glass filled with oil? If I succeed, I will write another book on this topic.
The last known brown fluid is "mud". It is a very familiar fluid; it doesn't smell, but it is dirty. I do not know, how this mud fits into our world, but it is just here. Nobody knows where it came from, nobody knows its use...
The most common fluid is water. It's a blue and opaque, you can't miss it. you can drink it, usualy it does not have any affections on the human body, but if the water comes from a very special place it is said to have healing powers!
Next, I will write about pink fluids. There are two kinds of pink fluids: wine and mysterious mana-regenerating fluid. What I told before about beer is exactly the same for wine. The other pink fluid seems to be very magical. Some people are able to produce this liquid; what a pity, all of these people sell it for horrendous prices!
Blood and a revitalising fluid are the two kinds of known red fluids. Blood, the "fluid of life", is a strange thing. Everyone will agree with me, that it is the "fluid of life", even though there are numerous living forms which do not have blood! Instead they seem to use some kind of slime (have a look the corresponding chapter to find out more about it). The life-restoring fluid is a strange fluid, too. I never was able to find out if it works on humans and on animals. I tried more than hundred times to heal my dog with it - but he does not want to drink it. As it seems, it only works for humans...
Last but not least, there exists one single white fluid in our world: People call it "milk".
There are rumours that it might increase one's magical abilties if swallowed - I never could verify this claim. As it seems, someone had dreamt about it and afterwards wasn't able to distinguish between reality and dreams...